Is there an effective way to determine if you are suffering from depression?

Eval: Symptoms of depression can include: feeling sad, irritable or angry. There can be a decrease in sex drive. Energy level & motivation levels may drop. One may socially isolate or stop involvement in normal activities. Sleep may increase or decrease. Weight can change in relation to increase or decrease in appetite. Concentration or memory may decline. There can be an absence of joy as well as >>.